IRIS-S122 (International Radio Interferometric Surveying - South) 1998 Jan. 29 Notes prepared by Arno Mueskens Geodetic Institute of the University of Bonn, Germany Schedule name: is122.skd on CDDISA [jan98] Nominal Start: 12:00 U.T. on Jan.29 (day 029) name yyddd-hhmmss Gc Hh Wf Wz Ft 1606+106 98029-120714| 70 70 70 70| 0805+410 98029-120000| 220 220 | 0229+131 98029-120001| 320 320 | Nominal Stop : 12:00 U.T. on Jan.30 (day 030) name yyddd-hhmmss Gc Hh Wf Wz Ft 1741-038 98030-114659| 70 70 70 | NRAO512 98030-115251| 70 100 100 100| 0955+476 98030-115842| 75 145 145 | Duration: 24 hours Correlator: BONN Purpose ======= The purpose of the IRIS-S sessions is to continue the series of measurements for the determination of earth rotation parameters. IRIS-S experiments are set up to provide all earth orientation parameters (UT1, polar motion, and nutation), baseline components and positions of extragalactic radio sources. With the addition of Fairbanks this network produced excellent EOP results. This network with long noth-south and east-west baselines as well as the wideband capability provides a good EOP determination even with the inclusion of the O'Higgins antenna. Network ======= The standard configuration of the monthly observed IRIS-S (South) experiments consists of four stations. One station in the United States(Westford,Ma), one station in South Africa(Hartebeesthoek), one radio telescope in Europe(Wettzell,Germany) and one radio telescope in South America(Fortaleza,Brasil). Since January 1997 the network is augmented by station Fairbanks(Alaska). During the O'Higgins occupations two more stations of the southern hemispere are added to this network. With O'Higgins and Hobart(Tasmania) we will have seven participate station in this network. Schedule ======== This schedule was generated by (auto)-SKED using the NEOS-WB frequency setup, using variable scan lengths with a minimum of : 70 seconds. The most recent source flux models are included. SNR goals are 20 at X-band and 15 at S-band for all baselines. On the baseline HartRAO-Fortaleza the SNR goal for the X-band is 30. The predicted SNRs used include a 30 ps noise contribution added in quadrature, which is a typical magnitude for the reweight constants applied in SOLVE solutions. The schedule is generated for the estimation of all five (seven) earth orientation parameters, clock offsets and clock rates for all participating stations except the reference station and atmo- sphere parameters for all participating stations. It was optimized for three earth orientation parameters (polar motion, UT1). Other optimization features enabled for this experiment : - the covariance analysis during schedule generation considers the previous 24 hours of observations, - minor SKED optimization parameters . maximum number of observations, . minimum time, . local coverage, were optimized over the best ( in a covariance sense ) 75% of the possible observations, this produces a somewhat more even sky distribution, - observations were weighted by their expected SNRs, - 30 ps noise contribution added, - mimimum time between observations of the same radio source was set to 25 min Procedures ========== NO PREPASS TIME: There is no time allowed in the schedule for prepassing tapes. Therefore all tapes needed for this experiment must be pre-checked before the start of this experiment. FREQUENCY SEQUENCE: The NEOS-wideband RF band frequency sequence ------------------ is used for this experiment. THIS SCHEDULE HAS A 10 SECOND EARLY TAPE START: ----------------------------------------------- To gain synchronization time at the correlator. REMARKS: ======= O'HIGGINS spring campaign canceled from German Ministry --------- FORTLEZA tagalong ----------------- Fortaleza was scheduled in the tagalong mode. Because it's not clear if Fortaleza will be up before end of January. WESTFORD and FAIRBANKS RECORDING ON THIN TAPES --------------------------------------------- Westford and Fairbanks (Gilcreek) will record this session at high (56kbpi) density !! Correlation =========== This experiment will be processed at Bonn in one correlation pass with all baselines to be correlated. An extra correlation report will be sent after completion. Appendix ======== SKED Summary from file is122.skd for experiment IRS122 (all scans with at least one subnet station) SOURCE |0 6 12 18 | #SCANS #OBS #Obs/bl 0003-066Ix x x x x I 5 7 1.9 0048-097I xxxx xxxx x x x x x I 13 28 5.9 0059+581Ixxxxxx x x x xxx x x xxxxxxx x x xx x x x xxxxI 33 118 18.9 0104-408I x I 1 1 .3 0119+115I x x xx xxx xx xx x xx x x I 17 37 7.6 0119+041I x x x x x xx x I 8 12 2.5 0229+131I x x x x x xx I 7 25 5.0 CTA26 I xx x x x x x x I 8 12 2.8 0402-362I x I 1 3 .9 0454-234I x xx x x I 5 9 2.8 0458-020I x x x x x I 5 7 1.6 0528+134I xxxxxx x xx x x xx x x xxx xxx xxxI 24 78 16.0 0552+398Ixx xx xxx xx x xx x x xx xx x xxxxxx xxxxxI 32 148 26.8 0718+793I x x x x x I 5 11 1.4 0727-115I xxxx x x x x xx I 10 28 6.0 0749+540Ixxxxx xx xxxxxxxxx x xxx xxxxxxx xxx xxx x xxxxI 38 132 20.6 0804+499I x x xI 3 9 1.2 0805+410I x x x I 3 5 .8 0823+033Ix x xx x x x xx x x x I 12 27 5.7 4C39.25 Ixxxxxxxxx xxxxxxxx x x x x xx x x xxxxxxI 32 165 30.3 OK290 I x x x x xxx x I 8 12 2.0 0955+476Ixx xx x xxxxxxx xxxxx xx xx x xx xxx xI 29 102 17.0 1034-293Ix xx x x x x I 7 13 3.8 1044+719Ix xxx x x xx x x xxx x xx xx x xxx xx x xxxxI 32 113 19.2 1124-186I x x x x I 4 10 3.1 1128+385I x x xxx x I 6 15 2.5 1300+580I x I 1 1 .1 1308+326I x xx xx x x x xxx x xx xx xx xI 21 50 8.0 1334-127I x x xx I 4 10 2.2 1351-018I x x x x xx I 6 10 2.3 1357+769Ix x x x x x x x x x x x I 12 41 8.2 1606+106I x x x xx x x x x xxx x xx x I 16 39 7.9 1622-253I x I 1 3 1.1 NRAO512 I xx x x x x xx xxxxxx xxxxxxxxxxxx xxx x x I 31 128 22.3 1726+455I x xx xx x x I 8 29 5.6 1739+522Ix x xx x x xx x xxxxx xx xxxxxxx xxx x x x xx xxI 34 125 20.7 1741-038I x xxxxx xxx xxx x x I 14 55 12.1 1749+096I x x x I 3 8 1.6 1921-293I x I 1 1 .3 2121+053I x I 1 3 .6 2145+067I x x x x x I 5 16 3.3 2234+282I x x x xx x x x x xxx I 12 44 7.6 Total scans, obs: 518 1690 Average number of obs. per baseline per source (normalized by up-time) = 5.7 Min = .0 Max = 41.9 (Baseline Hh-Wz on 4C39.25 ) RMS = 9.3 Total time: 1440 minutes ( 24.0 hours). Key: Gc=GILCREEK Hh=HARTRAO Wf=WESTFORD Wz=WETTZELL Ft=FORTLEZA Gc Hh Wf Wz Ft Avg % obs. time: 44 21 54 49 22 38 % cal. time: 4 1 5 4 2 3 % slew time: 21 20 18 14 23 19 % idle time: 29 57 21 31 51 38 # of tapes : .7 1.2 .8 2.7 1.3 total # scans: 401 120 437 403 177 307 # scans/hour : 16 5 18 16 7 12.8 Avg scan (sec): 95 151 108 106 109 113 # OF OBSERVATIONS BY BASELINE | Gc Hh Wf Wz Ft StnTotal ---------------------------------- Gc|401 32 370 293 123 711 Hh| 120 63 112 58 936 Wf| 437 323 161 453 Wz| 403 155 697 Ft| 177 583 Number of 2-station scans: 163 Number of 3-station scans: 229 Number of 4-station scans: 105 Number of 5-station scans: 21 Total # of scans, observations: 518 1690 Average baseline components for all observations Average XY = 5545. Average XZ = 5340. Average YZ = 5116. Average length = 6765.